Method for Operating a Washing Cycle and a Subsequent Drying Cycle in a Laundry Washer-Dryer

ABSTRACT

A laundry washer-dryer comprises a tub, a drum for storing laundry rotatably arranged inside the tub, an air circulation channel connected at a first end and at a second end to the tub, a blower for blowing the air through the air circulation channel, the tub and the drum, and a heat pump system having a compressor, an evaporator and a condenser, the evaporator and the condenser being arranged in the air circulation channel. A method for operating a washing cycle and a subsequent drying cycle in the laundry washer-dryer comprises performing the washing cycle, the washing cycle including at least one washing phase, at least one rinsing phase and at least one spinning phase, and performing the drying cycle including at least one drying phase. At least one last rinsing phase of the washing cycle is performed by using heated water so as to cause the temperature inside the tub to increase.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to European Application No. 10163727.0, filed on May 25, 2010.

BACKGROUND OF THE INVENTION

Aspects of the present invention relates to a method for operating a washing cycle and a subsequent drying cycle in a laundry washer-dryer with a heat pump system. Further, aspects of the present invention relates to a laundry washer-dryer with a heat pump system.

A laundry washer-dryer with heat pump technology is an efficient way to save energy during the drying cycle. The laundry washer-dryer allows a combined washing and drying cycle. After the laundry has been filled into the laundry washer-dryer by the user, the washing cycle and the subsequent drying cycle can be performed automatically. The user can take the washed and dried laundry from the laundry washer-dryer, after the drying cycle has been finished. It is not necessary for the user to open the door of the laundry washer-dryer between the washing cycle and the drying cycle.

However, during the initial phase of the drying cycle the operation is not particularly efficient, since the heat pump system requires a certain time in order to reach a steady state. For example, the heat pump system takes about 20 to 30 minutes for reaching the steady state after the beginning of the drying cycle.

SUMMARY OF SELECTED INVENTIVE ASPECTS

It is an object of the present invention to provide an improved method for operating the washing cycle and the subsequent drying cycle in a laundry washer-dryer comprising a tub, a drum for storing laundry rotatably arranged inside the tub, an air circulation channel connected at a first end and at a second end to the tub, a blower for blowing the air through the air circulation channel, the tub and the drum, a heat pump system having a compressor, an evaporator and a condenser, the evaporator and the condenser being arranged in the air circulation channel.

An object of the present invention can be achieved by the method according to claim 1.

According to an aspect of the present invention at least the last rinsing phase of the washing cycle is performed by using heated water.

The main idea of an aspect of the present invention is that at least the last rinsing phase before the drying cycle is performed by heated water. Due to the rinse by heated water, the temperature inside the tub and the drum is relative high, so that the initial heat exchange at the evaporator increases. The temperature of the evaporator increases, so that the refrigerant evaporates. Thus, more evaporated refrigerant enters the compressor during the initial phase of the operation of the heat pump system, and the compressor, in turn, more effectively compresses the refrigerant so that the temperature at the condenser increases more rapidly thereby reaching earlier the steady working condition of the heat pump system. This allows a more efficient heating up of the drying air at the initial stage of the operation of the heat pump system.

The rinse by heated water reduces the time interval for reaching the steady state of the heat pump system. This is particularly advantageous, if the drying cycle starts immediately after the rinsing phase by heated water and the subsequent spinning phase.

In practice, the last rinsing performed with hot/heated water causes an increase of temperature inside the tub and the additional heat is made available for the evaporator of the heat pump system via the air circulation channel that fluidly connects the tub to the evaporator.

The last rinsing performed with hot/heated water causes an increase of temperature inside the tub before the starting of the drying cycle, wherein the starting of the drying cycle can include the starting of the operation of the compressor of the heat pump system and/or the starting of operation of the blower for blowing the air through the air circulation channel.

In a preferred embodiment of the present invention, the compressor of the heat pump system is activated when the last rinsing phase performed with hot/heated water is running.

In a further preferred embodiment of the present invention, the compressor of the heat pump system is activated when a spinning phase subsequent to (following) the last rinsing phase performed with hot/heated water is running.

In a further preferred embodiment of the present invention, the compressor of the heat pump system is activated after the last rinsing phase performed with hot/heated water is completed.

In a further preferred embodiment of the present invention, the compressor of the heat pump system is activated after the spinning phase following the last rinsing phase performed with hot/heated water is completed.

In a further preferred embodiment of the present invention, the blower for blowing the air through the air circulation channel is activated after the last rinsing phase performed with hot/heated water is completed.

In a further preferred embodiment of the present invention, the blower for blowing the air through the air circulation channel is activated after the spinning phase following the last rinsing phase performed with hot/heated water is completed.

In a further preferred embodiment of the present invention, the starting of operation of the compressor can be provided before or after the activation of the blower for blowing the air through the air circulation channel.

In a further preferred embodiment of the present invention, the activation of blower for blowing the air through the air circulation channel can be provided before or after the starting of operation of the compressor.

According to a preferred embodiment of the present invention the washing phase and the subsequent rinsing phase are repeated for several times.

In a similar way, the drying phase is repeated for at least one time. This is particularly advantageous, if temperature-sensitive laundry is washed and dried.

Preferably, the amount of the laundry is equal or less than a value of a maximal amount of laundry for the drying cycle. The optimal amount of laundry for the drying cycle is less than the optimal amount of laundry for the washing cycle.

Further, the heated water may be generated by a heating device provided for a tub of the laundry washer-dryer. Thus, the heated water can be generated by a heating device, which is already available in the laundry washer-dryer.

In an alternative embodiment of the present invention the heated water is provided by a warm water supply. In this case a further water inlet with a valve is provided.

Additionally or alternatively, the heated water is provided by a renewable energy source. For example, the renewable energy source may be a solar collector or a photovoltaic cell.

Further, the temperature of the heated water may be between 40° C. and 80° C., in particular 60° C. The amount of the heated water may be between eight and twelve litres per rinsing phase.

Aspects of the present invention relate further to a laundry washer-dryer with a heat pump system, wherein the laundry washer-dryer is provided for a method described above.

For example, the laundry washer-dryer comprises a water inlet valve connected or connectable to a warm water supply.

Alternatively or additionally, the laundry washer-dryer comprises a heating device using at least one renewable energy source.

In particular, the laundry washer-dryer comprises a control unit programmed or programmable for performing the method described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the invention will be described in further detail with reference to the drawings, in which:

FIG. 1 illustrates a schematic flow chart diagram of a method for operating a washing cycle and a subsequent drying cycle in a laundry washer-dryer according to a preferred embodiment of the present invention, and

FIG. 2 illustrates a schematic diagram of the laundry washer-dryer with a heat pump system according to the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1 illustrates a schematic flow chart diagram of a method for operating a washing cycle 10 and a subsequent drying cycle 20 in a laundry washer-dryer according to a preferred embodiment of the present invention.

The first step of the method is a selection of the operation mode 12. By the selection 12 the user can select the cycle or cycles to be activated. In the preferred embodiment of the present invention the washing cycle 10 and the subsequent drying cycle 20 are activated by the cycle selection 12 so that the machine performs a complete washing-drying cycle without any further intervention of the user.

Alternatively, the washing cycle 10 without drying cycle 20 or the drying cycle 20 without washing cycle 10 may be activated.

Preferably, when a complete washing-drying cycle has been selected, the amount of laundry loaded into the drum is suitable for performing an effective drying without the need for the user to remove laundry before starting the drying cycle.

The first substantial part of the method is the washing cycle 10. The washing cycle 10 includes a washing phase 14 and a subsequent rinsing phase 16. During the washing phase 14 the laundry is handled by a cleaning agent. During the rinsing phase 16 the laundry is rinsed by water. The washing phase 12 and the subsequent rinsing phase 16 are usually repeated for several times.

The last rinsing phase 16 is performed by heated water. The previous rinsing phases 16 are usually performed by cold water. The heated water has a temperature between 40° C. and 80° C. Preferably, the temperature of the heated water is about 60° C. Additionally, rinsing phases previous to the last rinsing phase 16 can be performed by heated water. Further, several last rinsing phases 16 may be performed by heated water.

The last step of the washing cycle 10 is a spinning phase 18. During the spinning phase 18 water is removed from the laundry. After the spinning phase 18, the washing cycle 10 is concluded.

The second substantial part of the method is the drying cycle 20. The drying cycle 20 includes a drying phase 22 and preferably a cooling-down phase 24. The drying phase 22 is performed by the heat pump system.

Since the laundry has been handled by heated water during the last rinsing phase 16 or during several last rinsing phases 16 of the washing cycle, the temperature inside a tub of the laundry washer-dryer is relative high. The rinse by heated water reduces the time interval for reaching the steady state of the heat pump system. This is particularly advantageous, if the drying cycle starts after the rinsing phase 16 with heated water and preferably if a complete washing-drying cycle has been selected by the user.

FIG. 2 illustrates a schematic diagram of the laundry washer-dryer with a heat pump system according to the preferred embodiment of the present invention. The heat pump system comprises an air circuit 30 connected at a first end and at a second end to the tub and a refrigerant circuit 40.

The air circuit 30 includes a tub 32 with an integrated drum, an evaporator 34, a condenser 36 and a blower 38. The tub 32, the drum, the evaporator 34, the condenser 36 and the blower 38 are integrated within the air circuit 30. The drum is provided for receiving the laundry to be dried. The air circuit 30 may be formed as a closed or an open loop.

The refrigerant circuit 40 includes a compressor 42, the condenser 36, the evaporator 34 and an expansion device 44. The refrigerant circuit 40 forms a closed loop. The air circuit 30 and the refrigerant circuit 40 are thermally coupled by the evaporator 34 and the condenser 36. The evaporator 34 and the condenser 36 are air-fluid heat exchangers. In this example, the expansion device 44 is arranged within the evaporator 34. A cooling fan 46 is associated with the compressor 42.

Further, the air circuit 30 comprises a lint filter 48 and a water drain pump 50. The lint filter 48 is arranged between the drum and the evaporator 34. The water drain pump 50 is provided for removing condensed water.

Within the air circuit 30 the blower 38 blows an air flow through the tub 32, the drum, the lint filter 48, the evaporator 34 and the condenser 36. The warm and wet air flow coming from the drum 32 is cooled down in the evaporator 34, wherein the water vapour in said air is condensed in the evaporator 34. Then, the air flow is heated up in the condenser 36. At last, the air flow arrives at the blower 38 again.

A refrigerant circulates through the refrigerant circuit 40. The refrigerant is compressed and heated by the compressor 42. The heated refrigerant arrives at the condenser 36. In the condenser 36 the refrigerant is cooled down and condenses. At the same time, the air flow in the air circuit 30 is heated up. In the evaporator 34 the refrigerant is heated up, wherein at the same time the air flow in the air circuit 30 is cooled down. In the expansion device 44 the refrigerant is expanded and cooled down. At last, the refrigerant is compressed and heated up again by the compressor 42.

Due to the rinse by heated water, the temperature inside the tub 32 and the drum is relative high. Thus, the initial heat exchange in the evaporator 34 increases. Further, the temperature of the evaporator 34 increases, so that the refrigerant evaporates. Thus, the compressor 42 is able to compress the refrigerant in such way, that the temperature at the condenser 36 increases. This allows a more efficient heating up of the air flow at the initial stage of the operation of the heat pump system.

The water for the at least one last rinsing phase 16 may be heated up by that heater usually provided at the tub of the laundry washer-dryer. This is usually an electric heater.

Further, the heated water can be fed by a warm water supply. In this case the laundry washer-dryer is provided with two water inlets, i.e. the one water inlet for cold water and the other water inlet for warm water, wherein each water inlet comprises a valve. A combination of the warm water supply and the heater is also possible. This is reasonable, if the warm water supply delivers water at temperature being too low for the last rinsing phase 16.

Additionally, the warm water supply may be provided by a renewable energy source, e.g. a solar collector, a photovoltaic cell or they like.

The at least one last rinsing phase 16 with heated water can be automatically performed by a control unit of the laundry washer-dryer, when the user selects an operation mode, which changes directly from the washing cycle to the drying cycle. Alternatively, the last rinsing phase 16 with heated water may be automatically performed, when the user selects a special cycle or phase.

The present invention can also be embedded in a computer program product which comprises all the features enabling the implementation of the method described herein. Further, when loaded in computer system, said computer program product is able to carry out these methods.

Although an illustrative embodiment of the present invention has been described herein with reference to the accompanied drawings, it is to be understood that the present invention is not limited to that precise embodiment, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.

LIST OF REFERENCE NUMERALS

-   10 washing cycle -   12 selecting the operation mode -   14 washing phase -   16 rinsing phase -   18 spinning phase -   20 drying cycle -   22 drying phase -   24 cooling-down phase -   26 finishing the drying cycle -   30 air circuit -   32 drum -   34 evaporator -   36 condenser -   38 blower -   40 refrigerant circuit -   42 compressor -   44 expansion device -   46 cooling fan -   48 lint filter -   50 water drain pump 

1. A method comprising: performing a washing cycle including at least one washing phase, at least one rinsing phase and at least one spinning phase using a laundry washer-dryer, wherein the laundry washer-dryer comprises a tub, a drum for storing laundry rotatably arranged inside the tub, an air circulation channel connected at a first end and at a second end to the tub, a blower for blowing the air through the air circulation channel, the tub and the drum, and a heat pump system having a compressor, an evaporator and a condenser, the evaporator and the condenser being arranged in the air circulation channel, and the at least one rinsing phase is performed using heated water so as to cause the temperature inside the tub to increase; and performing a drying cycle including at least one drying phase.
 2. The method according to claim 1, wherein the at least one rinsing phase is at least partially performed before at least one of starting the operation of the compressor and starting the operation of the blower.
 3. The method according to claim 1, wherein the compressor starts to operate when a last rinsing phase is in progress or when a spinning phase subsequent to the last rinsing phase is in progress.
 4. The method according to claim 1, wherein the compressor starts to operate after a last rinsing phase is completed or after a spinning phase subsequent to the last rinsing phase is completed.
 5. The method according to claim 1, wherein the blower for blowing the air through the air circulation channel starts to operate after a last rinsing phase is completed or after a spinning phase subsequent to the last rinsing phase is completed.
 6. The method according to claim 1, wherein the starting of operation of the compressor is provided before or after the activation of the blower.
 7. The method according to claim 1, wherein the amount of the laundry is less than a value of a maximal amount of laundry for the drying cycle.
 8. The method according to claim 1, wherein the heated water is generated by a heating device provided for a tub of the laundry washer-dryer.
 9. The method according to claim 1, wherein the heated water is provided by a water supply.
 10. The method according to claim 1, wherein the heated water is provided by a renewable energy source.
 11. The method according to claim 1, wherein the temperature of the heated water is between 40° C. and 80° C., in particular 60° C.
 12. A laundry washer-dryer comprising: a tub; a drum configured for storing laundry and rotatably arranged inside the tub; an air circulation channel connected at a first end and at a second end to the tub; a blower configured for blowing air through the air circulation channel, the tub and the drum; and a heat pump system having a compressor, an evaporator and a condenser, the evaporator and the condenser being arranged in the air circulation channel, wherein the laundry washer-dryer is configured to perform a washing cycle including at least one washing phase, at least one rinsing phase and at least one spinning phase, the at least one rinsing phase performed using heated water so as to cause the temperature inside the tub to increase, and performing a drying cycle including at least one drying phase.
 13. The laundry washer-dryer according to claim 12, comprising a water inlet valve connected or connectable to a warm water supply.
 14. The laundry washer-dryer according to claim 12, comprising a heating device using at least one renewable energy source.
 15. The laundry washer-dryer according to claim 12, comprising a control unit programmed for performing the washing and drying cycles. 